We have heard him sing改为被动语态.He ____ ____ ____ ____ ____ by us.hear 后面不是不可以加to do 不定式吗,请注意要填五个空！
问题描述：
We have heard him sing改为被动语态.He ____ ____ ____ ____ ____ by us.
hear 后面不是不可以加to do 不定式吗,请注意要填五个空！
答
He had been heard to sing by us.
答
He was heard to be singing by us. 五个字就这个makes sense
It should be better as "He has been heard singing by us."
答
has been heard to sing 被动语态时"to do"是要还原的
答
We have heard him sing改为被动语态。
He sing has been heard by us.